Radiodetector



L. c. BLUME RADIODETBOTOR Filed June 28, 1923 I amulet:

Patented June 29, 1926 UETED STATES LOUIS C. BLUME, OF CHICAGO,ILLINOIS.

RADIODETECTOR.

Application filed June 28, 1928. Serial No. 648,305.

My invention relates, generally, to improvements in detectors for use inconnec* tion with wireless telephone apparatus and has particularreference to the so-called cat-whisker or galena detectors for wirelesstelephone receiving sets.

In using the ordinary cat-wl1isker or galena detector, considerabledifficulty is usually experienced in locating the most sensitive oreffective spot with the cat-whisker upon the crystal or other detectorbodies. The detectors of the prior art usually require an independentlocking means in the nature of a set screw or similar device for lockingthe cat-whisker in position upon the selected spot of the crystal. Itis, therefore, the primary object of my invention to furnish a novel andimproved detector of the character set forth, wherein the most sensitivespot of the crystal or detector body may be readily located, an improvedclamping means being employed for maintaining the cat-whisker in aselected position.

Another important object of the invention is to furnish a novel andimproved support for the cat-Whisker, means being provided for auniversal movement thereof.

The invention also has for an object to provide a detector of this kindembodying few parts, and which will be highly efficient in use althoughinexpensive of manufacture.

The above and other objects, which will become more apparent as thedescription proceeds, are attained by a novel combination andarrangement of parts to be hereinafter described and claimed, and inorder that the same may be better understood, reference is had to theaccompanying drawing forming a part of this specification.

In the drawing,

Figure l is an elevation of a detector con structed in accordance withmy invent-ion;

Fig. 2 is an end elevation thereof;

Fig. 3 is a side elevation of the support,

' partly broken and partly in section, showing the cat-whiskerattachment and associated members, and

Fig. 4 is a detail illustrating the head for supporting the cat-whisker.

Referring specifically to the drawing, wherein for the purpose ofillustration the preferred embodiment of the invention is disclosed, andin which like reference characters have been used throughout todesignate similar parts, numeral 5 denotes a base of insulatingmaterial, upon the upper face of which is supported a support 6 which isfastened to the base by means of a binding post .7 extending through abottom lateral flange of said support 6. The usual nut and washer 8'clamping above the lateral portion of the support 6 to maintain the samein place, while a suitable cap nut 8 serves to secure wires to thebinding post in the usual manner.

The upper portion of the support 6 terminates in an arcuate portion 9 ofsubstantially 180 degrees, this portion being provided with a closedarcuate slot 10 as best shown in Fig. 3 for the reception of a laterallyprojecting arm 11 for sliding movement therein. The arm '11 is providedwith a head 11 which engages with the inner face of the arcuate portion9 adj acent the slot 10, while a washer ll urged against the outer faceof the arcuate portion 9 serves to maintain the arm 11, in apredetermined position. The pin 11 is provided adjacent its outer endwith a transverse aperture through which extends for sliding movement acarrier pin 13, which latter is provided at its lower end with acircumferential groove 13 whereby a contact or cat-whisker carrying headmay be attached as will presently appear, and at its upper end with acap or finger piece 14:.

The cat-whisker carrying head is denoted at 15 and is provided with aportion for en gagement with the groove 13 of the pin 13. In thedrawings, I have illustrated the head 15 as being-substantially U-shapedand provided with a slot 15 in one of its arms for engaging the groove13 of the pin 13.

The other arm is adapted to carry upon 1ts outer face the contact wiresor cat-whiskers 16 as shown in Figs. 3 and 4. More specifically the head15 is formed from a single length of more or less resilient metal bentor otherwise arranged in U-shaped formation and having one of thebranches formed with a longitudinal slot which extends out through oneend thereof to define a pair of legs which engage in the circumferentialgroove 13* and thereby hold the U-shaped head in proper position. Itwill be seen that the U-shaped member 15 may be freely disconnected whendesired.

A plate 17 carried adjacent the other end of the upper face of theinsulated block 5 supports a metallic cup 18, the outer sur face ofwhich is knurled as shown at 19, the detector body 20 being secured orclamped therein by means of a set screw 20 passing through the side wallof the cup 18. The detector body may be of s'ulphuret of lead, commonlycalled galena, or any other suitable crystal mass commonly used for thispurpose. The plate 17 is fastened to the insulated block 5 by meansofrthe second binding post 22 which passes through a longitudinal slot21in-the end-of the plate. The usual washer and nut 22 and 2 respectively,serve to clamp; the plate in a predetermined position. The cap nut 23acts to s'ecur'e'wires to the binding post 22.

From the foregoingdescription, the-construction of my detector will bereadily appreciated by thoseskilled in the art Its operation may bebriefly summarized as follows:

The detector is coupled in an electrical circuit with other elements ofa wireless telephone receiving set by means of the bindposts '7 and 22.The crystals or other detector body substance of highelectricalconductivity is clamped in the cup 18 by means-of the setscrew 20'. The contact surface or face of this detector body ispreferably of a very o'ugh character, thereby providing a multiplicityof minute'contact surfaces and materially increasing the eneral utilityand servi'c'eability of the" device.

The electro-radiant waves-are transmitted through the detector body orcrystal port'i'on'QO and the cat-Whisker 16, froni'wlrence they 'pass'tothereceiver, the wave oscillations'being co-l'i-v'erted into a formforintelli gently transmitting the m'e'ssage' Without necessitatingthe use"of any auxiliar energy. The operator, owing to the univerthrough themedium'of the vertically slidable pin 13 and the ar'cu ately slidablepin 11 which may be rotatedin the slot 1001 the support 6, maybruslrtlre metal contact elements or cat-whiskers 16' over the faceofthe crystal or detector body 20 and elfect'ually locate-the mostsensitive "spot'tl'ierein. Figures '1 and 3- 'p'lainl'y illustrate thatthe upper po'rtion'oftlie supporting membereis provided with a-returnbend and the slot 10 is in this return bend so that, if

desired, the laterally projecting arm 11 may be swungup to permit thecatwhisker carrying head 15 to be easily disconnected or reapplied tothe pin 13. In other Words the cat whisker carrying head 15 may beremoved-a substantial distance from the crystal or piece of galena ascontact of the hand with 'theiga-lena frequently destroys thesensitiveness of the galena.

The spring "12 functions to tightly -press against the pin 13 and thewasher 11", thus serving to hold the pins Band 11 in the desiredposition; While the preferred enrbo'dimen't of'nry in-vention hasbeen'describ'ed and illustrated in accordance with the p'atentstatute's, yet it will be understood that various changes andmodifications mayi'b'e 'n'iad'e' therein without departing fronrfthespirit'of my invention,- thescope of which is clefi nedby the followingclaims.

Having thus described my invention, What I claim as new and desire tosecure by'IJet- 'ters Patent is:

'1. In a radio device, the combination or a -carrier having acircumferential :g'roove adjacent one end thereof,--of a u shaped headhaving a branch formed with "a slot opening out through one end thereofand defin'mga pair of legs to engagein said circumferential slot toconnect theh'ead to said carrier member, said U-shap'ed head having asecond branch, anda cat Whisker carried by said second branch;

branch and a cat whisker carried by said second branch.

Intestnnony whereof I affix my signature.

' Louis e. BLUME.

